HP Surestore Disk Array 12h and FC60 - Manual (Page 184)

184 Attaching Power Cords
letters among all disk enclosures. “Cascading” refers to overload faults that occur on
a backup PDU as a result of power surges after the primary PDU fails.
– Serviceability. Choose PDU locations that prevent power cords from interfering
with the removal and replacement of serviceable components. Also leave a 6-inch
service loop to allow for the rotation of PDRUs.
The letters A, B, C, D, E and F in Figure 66 and Figure 67 represent independent PDUs or
PDU banks. The absence of duplicate letters in individual sorage systems indicates the
products are using redundant PDUs. The minimum number of duplicate pairs of letters in
all sorage systems indicates the products are protected against cascading faults.